As MD lawmakers consider rules to govern fracking, they are also looking toward a permanent ban.

A General Assembly hearing Tuesday on regulations to protect water quality and public health if fracking begins in Maryland foreshadowed an imminent fight over whether to ban the natural gas-extraction process before the proposed rules could even take effect next year.

Maryland Environment Secretary Ben Grumbles called the rules a "platinum package," a step up from the "gold standard" former Gov. Martin O'Malley applied in fracking rules his administration released early in 2015.

Grumbles said the new regulations, unlike O'Malley's rules, would prohibit fracking within the Deep Creek Lake watershed in Garrett County and require quadruple layers of cement and steel around wells and deep safety valves.

Western Maryland residents urged a joint legislative panel to approve the rules and foster economic growth in the region, home to a strip of gas-rich Marcellus shale.

But physicians, first responders and a top state geologist said the rules would not ensure that fracking won't lead to drinking water contamination and public health risks. Fracking opponents went a step further, urging state lawmakers to reject the regulations altogether and focus on banning fracking in Maryland when they return for the legislative session that begins in January.

Sen. Roger Manno, a Montgomery County Democrat who is co-chairman of the committee, said he expects lawmakers to put the rules on hold until at least February — when he expects the legislature to be considering at least one bill to ban fracking. Members of the joint committee charged with regulatory review were already discussing how to overturn a possible veto by Republican Gov. Larry Hogan if a ban passes.

"I think we're going to have to deal with this statutorily during the session," said Del. Dan Morhaim, a Baltimore County Democrat, after peppering Grumbles with questions about what he called weaknesses in the rules.

A spokesman for Hogan did not immediately respond to a request for comment.

The practice of hydraulic fracturing, commonly called fracking, involves injecting fluids at high pressure into the Marcellus shale to break up the rock and release natural gas stored within it.

The energy industry and environmentalists have long battled over the safety of fracking. A 2015 Environmental Protection Agency study found no evidence of widespread water contamination caused by the practice, but a final version published last week reversed course, saying such pollution has occurred.

Grumbles acknowledged the recent study and said that the rules would go further than those imposed in any other state to keep fracking safe. But for fracking opponents, they are still not enough.

"We recognize there are those convinced that no fracking should occur," he said, to applause from the dozens of fracking opponents in attendance. "I truly respect the differing opinions and views."

Former state delegate and Democratic gubernatorial candidate Heather Mizeur said that after three years serving on a state commission investigating fracking, she was convinced nothing could guarantee safety.

"It's all an illusion," she said. "We cannot guarantee the safety of our water and our environment and our local economy unless we keep this extreme extraction technique at bay."

David Vanko, a Towson University geology professor who chaired the fracking commission, expressed concern that Grumbles' rules, unlike those developed under O'Malley, don't give the state authority to approve gas well site plans.

He also said ancillary structures on fracking sites, not just the wells themselves, should be subject to setback requirements, and the state should charge well operators a tax whose proceeds would be used to clean up after any leaks, spills or other contamination.

Members of the group Chesapeake Physicians for Social Responsibility stressed that the most recent studies show links between fracking and health problems like premature births and asthma.

Mark Richards, a retired Howard County assistant fire chief and a Garrett County resident, said he was concerned that first responders won't have information on what chemicals could be coming out of wells if they are called to a site.

Representatives for the trucking and energy industries said the rules would be expensive to follow. Louis Campion, president of the Maryland Motor Truck Association, called them "achievable," but Drew Cobbs, executive director of the Maryland Petroleum Council, called them "overly restrictive."

Billy Bishoff spoke on behalf of Garrett County farmers and property owners. "We have a right to produce our gas if we want to," he said.

Some areas of the state have already been declared off-limits to fracking — the Baltimore County Council approved a ban Monday, joining the likes of the Western Maryland town of Friendsville. The Frostburg City Council voted this month to ban fracking on city-owned land.

Manno said Tuesday the committee planned to ask the attorney general's office whether the proposed regulations would supersede any of those local fracking bans.